1. Field of the Invention
The present invention relates to water quality sensor technology and more particularly, to a water quality sensor suitable for automated production to achieve enhanced production efficiency and to effectively reduce the manufacturing costs, which comprises a housing, a sensing module comprising a circuit board mounted inside the housing, two identical connectors mounted on the circuit board in reversed directions with a phase difference of 180 degrees therebetween, and a light emitter and a light receiver respectively mounted in the connectors to face toward each other for water quality detection.
2. Description of the Related Art
With the continuous progress in electronic technology, many easy-to-use household electrical appliances have been continuously created. In our daily lives, we use different household electrical appliances to handle different jobs rapidly, saving much labor and time. Many household appliances such as washing machines, dishwashers, and the like are designed for use with water and a cleaning fluid or detergent to achieve cleaning. Thus, we can use these household appliances to wash clothes, dishes, kitchen utensils, etc., instead of hand washing.
Further, when washing some objects in an electric washing machine, dust, debris and other impurities in the objects and the applied cleaning fluid or detergent can cause an increase in the turbidity of the applied water. Thus, the cleaning operation must be repeated several times until the objects to be cleaned are well cleaned. Most electric washing appliances are equipped with a water quality sensor to detect the turbidity of the applied water so that the control system can determine the cleaning mode according to the detected turbidity, enhancing the effectiveness of washing and achieving the purpose of energy saving. Further, water quality sensors are often installed in rivers or water supply areas where water is supplied to meet the needs of people's livelihoods. However, conventional water quality sensors are expensive and commonly designed for industrial applications, in consequence, water quality sensors are not popularly used in houses. Therefore, how to reduce the production cost of water quality sensors has been a big problem for manufacturers.
FIG. 10 illustrates a water quality sensor according to the prior art. According to this design, the water quality sensor comprises a housing (not shown), and a sensing module A mounted in the housing. The sensing module A comprises a circuit substrate A1, which comprises two arms A11 arranged in parallel, a notch A12 located on a front end of each arm A11 and a hook hole A13 located on an opposing rear end of each arm A11, a positioning block A2, which comprises two extension portions A21, a receptacle A211 located on each extension portion A21 of the positioning block A2, a positioning rod A22 located at one end of each extension portion A21 and a hook block A23 located at an opposite end of each extension portion A21, a light emitter A3 mounted in the receptacle A211 at one extension portion A21, and a light receiver A4 mounted in the receptacle A211 at the other extension portion A21. When mounting the positioning block A2 on the circuit substrate A1, tilt the positioning block A2 forward by an angle to force the positioning rods A22 into engagement with the respective notches A12 at the respective arms A11, and then impart a downward pressure to the positioning block A2 to force the two hook blocks A23 into engagement with the respective hook holes A13 of the circuit substrate A1.
The assembly process of the aforesaid prior art water quality sensor needs to be performed by labor, not suitable to automated production. In recent years, the labor and operating costs in the manufacturing industry keep increasing. Further, the additional costs associated with poor manual assembly result in a high rate (about 49%) of the manual assembly cost in the total production cost. In the assembly process of the aforesaid prior art design, mounting the positioning block A2 on the circuit substrate A1 needs to tilt the positioning block A2 forward by an angle to force the positioning rods A22 into engagement with the respective notches A12 at the respective arms A11. This procedure cannot be performed using an automatic plug-in. The manual assembly process to install the positioning block A2 in the circuit substrate A1 wastes much labor and time, resulting in poor production efficiency. Further, the positioning block A2 has a complicated structure, and thus, the related mold designing and manufacturing costs are increased. Therefore, there is a strong demand for a water quality sensor that is suitable for automated product to improve the production efficiency and to reduce to manufacturing cost.